Variable-stroke motor or pump.



H. S. HELE-SHAW.

VARIABLE STROKE MOTOR 0R PUMP 'APPLICATION FILED MAY 19. 1909.

6 SHEETS-SHEET I.

Patented Sept. 7, 1915.

H. S. HEM-SHAW, VARIABLE STROKE MOTOR 0R.PUMP. APPLICATION Flu-:0 MAY 19. 1909.

Patented Sept. 7, 1915;

6 SHEETSSHEET 2.

v H.- s. HELE-SHAW. 'L'AmABLI-I STROKE MOTOR on PUMP.

V I. APPLIQATION FILED MAYIQ. I909- 1,152,729. PatentedSept. 7,1915.

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. 3 w A Lg g B R s- 4 D H. S. HELE-SHAW. VARIABLE STROKE MOTOR 0R PUMP.

APPLIC ATION FILED MAY 19, I909. 1,152,

4, z 2 v Z74; 1.

' fi'akzZoZ- .Z feZevSkaW a I Womy J m w s'rn'rns Parana or HENRY SELBY HELE-SHAW, OF LONDON, ENGLAND.

VARIABLE-STROKE MOTOR OB PUMP.

Specification of Letters Patent.

Patented Sept; '7, 19f5.

Application filed May 19, 1909. Serial No. 496,957.

tors or Pumps, of which the following is a specification.

This invention relates to improvements in and connected with hydraulic apparatus and has reference to a machine which can be used either as a pump or as a motor or where two similar machines are combined in a fluid circuit as a variable transmission gear.

The present invention has reference to machines of the type where radial cylinders rotate relatively to a stationary valve and consists of a particular construction of such apparatus involving certain essential and fundamental features. I

The primary feature of the invention consists in the employment in combination with a central valve through which the liquid All the piston passes radially to and from the cylinders of a rotatable floating stroke controlling ring which rotates in company with the pistons essentially characteristic of iston heads with this ring. eads are free to move relanection of the I tively to the ring and in fact when there is any eccentricity between the stroke controlling ring and, the central valve, some slight relative movement must take place. By the combination of this floating ring with the radial valve all the forces exerted .by the pistons upon the ring are transmitted in the plane of rotation, a point which I have proved by experiment to be of paramount importance in practical working. As a' consequence of the detachment of the piston heads from the stroke controlling ring, it is necessary to provide some means for holding the piston heads up to the ring at all'parts of the revolution and a further feature of my invention consists of a compensating ring engaging the piston heads and-always maintain position concentric with the floating ring.

Other features of importance consist in "the employment of slippers capable of an- 'gular movement carried by the piston heads and coiiperating with a stroke controlling ring which is essentially rotatable or floating since the use of slippers with a nonrotatable ring has been found impracticable, unless special forced lubrication is provided.

Further features of my invention consist of several constructions of slippers provided with means for forcing a film of oil under the shpper and the special arrangement and combinations of parts set forth in the claims. In the accompanying drawings Figure 1 1s a sectional elevation of a form of my apparatus specially designed for use as a pump. Fig. 2 is a similar view of a modified form of the apparatus designed especially for use as a motor. Fig. 3 is a similar 4 View illustrating the manner in which the devices show in Figs. 1 and 2 can be combined in a achine to form a transmission gear. Fig. 4 is a longitudinal sectional view of a modified form of two of the devices shown in Fig. l, and showing how they can be combined to form a variable speed transmission gear. Fig. 5 is an end sectional view on line A-A of Fig. 4. Figs. 6 and 7 are sectional views on line B-B and (3-0 respectively of Fig. 1 of the stationary valve. Figs. 8 and 9 are sectional views at right angles to each other of a modified form of slipper, and Figs. 10 and '11 aresectional views illustrating a slipper provided with a ball valve.

Referring to these drawings and particularly to Fig. 1, A designates the induction pipe and B the eduction pipe of a construction of my apparatus designed primarilg for use as a pump. These pipes A and are connected respectively to the low and high pressure sides 1 and 2 of the central cylindrical stationary valve 3, the high pressure side 2 of which is divided from the low pressure side 1 by means of a longitudinal diaphragm 4. This-cylindrical valve 3 has inlet and outlet ports 5 and 6 respectively cut in it, and a cylinder body 7 is mounted to rotate upon this valve so that the open ends of the cylinders 8 cooperate with these ports as the cylinder body 7 rotates upon the stationary valve 3. The cylinders 8 are arranged in the cylinder body 7 preferably in more than one row and. the cylinders of one row are staggered in position relative to the cylinders of the next row; The cylinder body 7 is connected" up .to a driving wheel or pulle 9 by means of which the cylinder body 1s, when the pump is in operation, continuously driven. vPistons 10 work in the cylinders 8 and these pistons carry out their outer ends .slippers 11 which the cylinderbogjy'7 aiid its attached wheel I are capable of moving upon the ball heads 57 of the, pistons. Surrounding these plstons and cylinders a ring or drum 13 1s arranged andthis ring or drum 13 is capable valve 3. The axes of the cylindrical valve 3 and the drum 13 are always either coincident or parallel. In operation the cylinder body 7 is continuously rotated, ball bearings 15 preferably being provided to reduce friction. If the'axes of the valve 3 and the drum 13 are coincident the slippers 11 merely rotate. in contact with the inner periphery of the drum 13 and no flow of liquid takes place. If however, the axis of the drum 13 is moved so that the said drum 13 is situated eccentrically inrelation to the valve 3 reciprocating movement will beimparted to thepistons 10, and this reciprocation will cause fluid to enter the valve and cylinders from the pipe A on the low pressure or suction side 1 of the diaphragm 4 and be expelled from these cylinders and valve through the pipe B on the high pressure side 2 of such valve 3. By this means a continuous flow of liquid is assured. By altering the relative positions of the axes of the valve 3 and drum 13, that is to say by altering the degree of eccentricity between the valve 3 and drum 13, the length of the stroke of the pistons 10 is altered and thus an effective variable stroke pump is rovided.

f, instead of utilizing the apparatus as a pump, in the manner before described,

fluid under pressure is supplied through one or the other of the passages 1 and 2 of the valve 3 the apparatus willoperate as a motor, the reciprocation of the pistons 10 causing the slippers 11 td so operate,-'ih conjunction w ith the inner periphery of the drum 13, *a'sl-to cause bodily rotation of or pulley 9 and it follows that the speed of r0tat1on of the wheel will be infinitely variable at will by bearing the stroke of the"pistons in the manner before described. I prefer, however, where the motor is requlred, to einploy the particular. design shown in Fig. 2, in accordance, with the same principles as the apparatus before described, differs somewhat lnmatters of construction. The differences in this construction are however, confined to the provision of a floating liner or inner drum 13 capable 'of rotation within the non-rotatable drum 13, rollers 13 being I irterposed, between the two drums 13 and" i Q In addition to this the slippers 11 carried byzthe iston heads, in the construction shown in ig. 1, are replaced in this instance by rollers 16. The action of the apdrum or lining 13 which, although operating.

paratus is exactly similar to that of the form of my apparatus shown in Fig. 1, that is to say, fluid under pressure within one or other of the passages 1 or 2 of the stationary valve-3,will cause the reciprocation of the pistons 10 and the rollers 16 operating against the inner periphery of the floating causes the bodily rotation of the cylinder body 7 and its attached driving wheel. It should be noted in this case that the inner floating drum or liner 13 rotates bodily in company with the pistons 10 there being merely a small relative movement between the drum 13 and the roller 16, due to the fact that the distances apart of the rollers 16 measured along the circular path are continuously alterin owing to there being an eccentricity bedrums 13 and 13. Here also it will be understood that although primarily designed for use as a motor this construction of my invention may be utilized as a pump, in which case the cylinder body 7 will, of course, be continuously rotated.

In order to insure the piston heads, car rying either the slippers 11 or the rollers 16, always being held up to their work, I provide aring or rings 23 which are seated in therecessed portions 23 of the pistons 10, and it will be noted that these rings are used, in connection with each machine with which ring 23 the heads of the pistons en gage, the ring 23 always maintaining position concentric with the eccentric ring or drum 13. By this means the pistons are always maintained in proper working relation to said ring or drum 13, or, in the construction shown in. Fig. 2, to the inner floating ring 13 of said ring or drum 13. In Fig. 4 I have shown two structures similar to those shown in the former figures, as applied to a single shaft to form a variable speed transmission, to be hereinafter more fully described.

Referring to Fig. '5 the numeral 3 designates a central cylindrical valve, the high pressure side 2 of which is divided from the low pressure side 2 by suitable form of diaphragm 4. Ports 5 and 6 are out leading from the low and high pressure sides respectively of the valve and the liquid passes readily through these ports to and from the cylinders 7 which are mounted to rotate bodily upon the valve 3. The cylinders, of which there may be 'many, preferably odd number, may be arranged in more than one row if desired and those in one row may be staggered relatively to those in the next. All the cylinders are, however, rigidly connected and rotate in one mass, means such for instance as the shaft 17 being provided to enable the rotary motion to be imparted,

a motor in tween the cylinder body 7 and the eccentric H the manner which will be hereinafter made clear. The cylinders 7 have pistons 8 associated with them, and these pistons 8 carry rollers or other devices 16. A stroke controlling ring or drum 13 is provided and the devices 16 cooperate with this ring and the stroke of the pistons and the velocity and direction of flow of the liquid is dependent upon the position of this ring rela- I tive to the central stationary valve 3. That is to say, .the direction of the flow is dependent on which side of the valve axis the axis of the ring or drum 13 is located, and the stroke of the pistons'and velocity of the liquid is dependent on the distance separating the two axes. The ring 13 is what may be termed a floating ring, and is supported by and operates on the roller bearings11 which in turn are supported by the bracket 42, shown more clearly by Fig. 4 of the drawings. There is of course a small relative movement between the piston heads and this ring 13 which varies with the degree of eccentricity between the ring 13 and the valve 3. In order to maintain the rollers or other devices 16 in proper working relation with the ring or drum 13*, I provide compensating rings 23 which engage the piston heads, such rings 23 always maintaining position concentric with the floating ring or drum 13.

Some means must be provided for enablingthe position of. the ring or drum 13 to be arranged in yarious positions of eccentricity to the valve 3, and in the case of small sizedapparatus a simple form of push rod can'be provided and although this is all that is really necessary, I have shown by way of example one means of moving this ring. The particular mechanism shown consists of a shaft 37 carrying eccentrics 40 which engage in straps 15' in the heads of the slides 42 which carry thering or drum 13*. Y The shaft 37 has keyed upon it a worm "wheel 39 and a worm 38 meshes with this worm wheel. It will readily be under- -stood that the operation of this worm by means of a handle arranged outside of the casing 19' of the apparatus will cause the rotation of, the shaft 37 and theconsequent movement of the eccentric 40' will cause eccentricity to be imparted to the ring or drum 13. In operation of the apparatus as a pump the cylinders 8 are continuously rotated. If the ring or drum 13 is arranged concentric with the valve 3, no flow of liquid will take place, but if some eccentricity is imparted to the ring or drum'13, the liquid will flow into the cylinders from what is at the moment the influx side of the valve 3 and outgof the cylinders into what is at the is supplied to the valve, the cylinder will be caused to bodily rotate and the speed of rotation will depend upon the degree of eccentricity of the ring or drum 13 or in other words upon the stroke of the pistons.

In Figs. 3 and 4 I have shown one method of combining two of the devices similar to those shown in Fig. 1 to forma variable speed gear. Referring to these figures, P designates one hydraulic device acting for the moment as a pump, and M designates a common stationary valve 3 which is supported by the frame. The cylinders fit accurately so as to be capable of revolving liquid tight. Upon parts where the cylinders are mounted the valve is provided with inlet and outlet ports 5 and 6, which ports cooperate with the open ends of the cylinders 8 and 8 as such cylinders rotat'e bodily upon the said tube, in a manner which will hereinafter be made clear. The dividing diaphragm 4 of the alve 3 is inthis example constructed in the form of a bearin as shown, and a solid transmission shaft 1 is "supported in this bearing, while the ends of the shaft 17 are further supported by the ball bearings 31 and 32' carried by the casing 19' of the apparatus as a whole, while at these parts where the shaft 17 passes out of the casing on either side, stufiing boxes are provided. Upon one end off the shaft- 17, that is the end nearest the source of power, which the apparatus is designed to transmit, a sleeve 35 is revolubly mounted and it is really this sleeve with the shaft within it which is supported by the ball bearings 32.

The other end of the'shaft 17 is preferably of somewhat larger diameter than the body of the shaft as a whole, but it may be exactly similar to. the other end, the enlarged portion of the shaft is, however, secured to the cylinders 8, and this enlarged portion of the shaft is directly supported by the ball bearings 31'. The sleeve 35' has a flange 36 and is, by means of this flange, connected to the cylinders 8' of the hydraulic device P, which cylinders it always carries around with it when the apparatus is in operation. Similarly the enlarged end of the shaft 17 has a flange 37 by means of which such shaft is-connected to and is driven by the cylinders 8 of the hydraulic device M. The cylinders 8 and8' have pistons 10 working in them and these pistons carry rollers or equivalent devices 16 at their heads, and these rollers for instance make contact with the inner peripheries of the floating drums 13 which embraces them. In order to maintain the rollers 16 at the piston heads in proper working relation with the floating drums 13 and 14, I provide compensating rings 23 which engage the piston heads, such rings 23 always maintaining positions con centric with the floating drums With which they are associated.

The floating drums 13 and H al-e mounted upon ball bearings 11 carried by nonrotatable rings 45 and 46, which, as will be seen, are in general, placed eccentrically, these eccentric rings 45 and 46 are, however, so mounted in or upon supports or guides 47 rigidly secured to the casing 19' of the apparatus as to be capable of lateral sliding movement/ By this means it will be readily understood that the floating drums 13. and 14 can be arranged so as to be concentric with the main axis of the apparatus, which as aforesaid, is the axis of the valve 3 or such floating drums 13 and 14: can be arranged in various positions eccentric to the main axis of the apparatus. It will thus be seen that provision is made whereby any degree of eccentricity, in either direction can be imparted independently to each of the said floating drums, thus enabling the speed and direction of rotation of the driving mechanism to be varied and reversed, respectively. The floating drums 13* and 14 are as aforesaid, eachindependently adjustable, the mechanism hereinbefore described being duplicated as shown although it"is not absolutely necessary that both devices should be variable. In order to provide for the central support of the shaft 37, I provide a bearing 53 in the central portion or diaphragm 54' of the casing 19- in which the inner end of one of the shafts 37' is mounted, while the inner end of the other shafts 37 is reduced and is journaled in a recess provided forthe purpose in the inner end of the opposing shaft. The casing partition 54 also serves as a central support for the stationary valve 3 and may be also utilized to carry any suitable form of safety valve 55'.

The operation of this form of my apparatus is as follows :Assuming that the sleeve 35 and the shaft 17 are unclutched from each other, the sleeve 35' will, as aforesaid, be driven and the cylinders 8 of the first hydraulic device P will be carried around. If the floating rings or drums 13 and 14* are both in their middle position, that is, the positions where their axes are coincident with the main axis of the apparatus, theoil or other liquid with which the apparatus is filled will not be circulated and the cylinders 8 will rotate idly. If, however, some eccentricity is imparted to the floating rings or drums 13. and'14 the hydraulic device P will act as a pump to an I extent dependent on the degree of eccentricity of the corresponding cylindrical drum 13 and the second hydraulic device M will consequentlyact as the motor and the relative velocity ratios of the sleeve 35 driven from the engine, andthe driven shaft '17 driven by the cylinders 8 will depend action is set up which causes reciprocatingmovement to be imparted to the pistons 10 of the cylinders 8, and, this reciprocating 'movement of these latter pistons 10 against the periphery of the floating drum 14 causes the bodily rotation of the cylinders 8 and the shaft 17 attached to them in company with the floating drum 14 which floats around with them.

If the eccentricities of the drums are equal and opposite, the shaft 17 will rotate at the same speed as the sleeve 35 is driven by the engine. Instead of employing rollers at the head of the pistons I may provide slippers such as 11 shown in Figs. 8, 9, 10 and 11. In this case the pistons 10 are provided with ball heads 57 upon which the slippers have angular movement. The slippers cooperate with the floating rings 13 and 14, not shown by these figures, but clearly shown by Fig. 4 of the drawings. Fig. 8 shows a slipper provided with grooves 57 for receiving compensating rings 23 which serve to keep the slippers in correct relation with the rings or drums 13 and 14: with which the pistons cooperate. In order to provide against any tendency of the slippers to adhere to or frictionally grip the floating rings or drums when pressure is applied, I may provide the forced lubrication or pressure balancing device shown in Figs. 8 and 9. In this case the piston proper 10 has a small piston 26 within it, a spring 27 serving to keep these small istons 26 out until the pressure rises su ciently to overcome the pressure of said spring 27. The pistons proper 10 are bored almost directly through, the side ducts 28 shown by Fig. 9, lead from this bore into chambers 29 which in turn have passages 30 leading to the surface of the slipper. It will thus be clear that as the pressure rises oil is forced out of the passages 30 and the pressure of fluid seeks to lift theslipper from the drum and as a consequence said slipper floats off on a film of oil when oil is the fluid with which the casing is supplied. Immediately the pressure upon the small piston 26 is so much reduced that the spring 27 can operate to move the small piston 26, such movement will cause return valve 35.

piston head through and continue the orifice through the slipper.

In Figs. 10 and 11 I have shown how a ball valve may be employed. The pistons 10 are in this case bored directly through the surfaces of the slipper and a valve seating 31 is provided to seat the ball 32 which is prevented from falling out by the retaining fitting 33. It will be understood that at starting, the fluid will escape through the orifice 34. and to the outside surface of the slipper, but almost immediately the ball will close down upon its seat to the pressure of fluid behind it, and thus if the fluid be oiled, effective lubrication will be provided for without any undue waste or leakage of the oil.

I claim- 1. The fluid machine comprising the combination of a cylindrical valve provided with ports, radial cylinders rotatable relative to said valve and having ports cotiperating radially with the ports of said valve,

pistons operating in thecylinders; a ring mounted eccentrically in relation to the primary axis of rotation with which ring the pistons cooperate without definite attachment, and a compensating ring engaging the piston heads and always maintaining position concentric with the eccentric ring.

2. The fluidmachine comprising the combination with a cylindrical valve provided with ports, radial cylinders rotatable relative to said valve and having ports coiiperating with the ports of said valve, and pistons operating in the cylinders; of a ring mounted eccentrically in relation to the primary axis of rotation with which ring the pistons coiiperate without definite attachment, slippers capable of angular movement carried by the piston heads, and passages leading from the outside of said slippers and communicating. with fluid within the pistons and means for controlling the flow of fluid through said passages.

3. The fluid machine comprising the com-' bination of a cylindrical valve provided with ports, radial cylinders rotatable relative to said valve and having ports coiiperating radially with the ports of said valve, pistons operating in the cylinders; a ring mounted eccentrically in relation to the primary axis of rotation with which ring the pistons coiiperate without definite attachment, a compensating ring engaging the piston heads and always maintaining position concentric with the eccentric ring, and slippers capable of angular movement carried by the pistonheads.

4. The fluid machine comprising the combination with a circular valve provided with ports, radial cylinders rotatable relative to said valve and having ports cooperating with the ports of said valve, and pistons operating in the cylinders; of a ring mounted eccentrically in relation to the primary axis of rotation, with which ring the pistons coiiperate without definite attachment,

a ring engaging the piston heads and always maintaining position concentric with the cocentric ring, slippers capable of angular movement carried by the piston heads, and passages leading from the outside of said slippers and communicating with fluid within the pistons and means for controlling the flow of liquid through said passages.

5; The fluid machine comprising the combination of a cylindrical valve provided with ports, radial cylinders rotatable relative to said valve and having ports cooperating radially with the ports of said valve pistons operating in the cylinders; a ring mounted eccentrically in relation to the primary axis. of rotation with which ring the pistons cooperate without definite attachment, means for varying theeccentricity of the ring, and a compensating ring engaging the piston heads and always maintaining position concentric with the eccentric ring.

6. A fluid machine comprising the combi- I nation of a cylindrical valve provided with ports, radial cylinders rotatable relative to said valve, and having ports cotiperating radially with the ports of said valve, pistons operating in the cylinders, a floating ring rotatable in company with the pistons and mounted eccentrically in relation of the pri-' mary axis of rotation with which ring the pistons coiiperate without definite attachment, a compensating ring engaging the piston heads and always maintaining position concentric with the eccentric ring, and slippers capable of angular movement carried by the piston heads.

7 The fluid machine comprising the combination with a circular valve provided with ports, radial cylinders rotatable relative to said valve and having ports coiiperating with the ports of said valve and pistons op- 7 through said passages. I

8. The fluid machine comprising the combination with a circular valve provided with ports, radial cylinders rotatable relative to said valve and having ports cofiperating with the ports of said valve and pistons operating in the cylinders; of a ring rotatable in company with the pistons and mounted eccentrically in relation to the primary axis of'rotation, with which ring the pistons cooperate without definite attachment, slippers capable of angular movement carried by the piston heads, and passages leading from the outside of said slippers and communicating with fluid within the pistons and means for controlling the flow of liquid through said passages. v

9. The fluid machine comprising the combination of a cylindrical valve provided with ports, radial cylinders rotatable relative to said 'valve and having ports cooperating radially with the ports of said valve pistons operating in the cylinders; a ring rotatable in company with the pistons and mounted eccentrically in relation to the primary axis of rotation with which ring the pistons cooperate without definite attachment, 7 a compensating ring engaging the piston heads and always maintaining position concentric with the eccentric ring, and

slippers capable of angular movement caring ring rotatab e in company with the pis V tricity of the ring,

with ports,

ried by the piston heads.

10. Thefluid machine comprising the combination with a circular valve provided radial cylinders rotatable relative to said valve and having ports cooperating with the ports of said valve and pistons operating in the cylinders; of a ring rotatable in company with the pistons and mounted eccentrically in relation to the primary axis of rotation, with which ring the plstons coiiperate without definite at-' tachment,.a ring engaging the piston heads and always maintaining position concentric with the eccentric ring, slippers capable of angular movement carried by the piston heads, and passages leading from the outside of said slippers and communicating with fluid within the pistons and means for controlling the flow of fluid through said passages.

11. The fluid machine comprising the combination of a cylindrical valve provided with-ports, radial cylinders rotatable relativeto said valve and having orts 006perating radially with the ports 0 said valve, pistons operatin in the cylinders of a floattons and mounted eccentrically in relation to the primary axis of rotation, with which ring the pistons 0015 rate without definite attachment, means or varying the eccenand a compensating ring engaging the piston heads and always mainaining position concentric with the eccentric rin a 12. file fluid machine comprising the combination of a cylindrical valve provided with ports, radial cylinders rotatable relative to said valve and'having ports cooperating radially with the ports of said valve, pistons operating in the cylinders, of a floating ring rotatable in company with the pistons and mounted eccentrically in relation to the primary axis of rotation, with which attachment, means for varying the eccentricity of the ring, a compensating ring engaging the piston heads and always maintaining position concentric with the eccentric ring, heads for pistons.

13. The fluid machine combination of a circular valve provided with ports, radial cylinders rotatable relative to said valve and having ports cooperating radially with the ports of said valve, pistons operating in the cylinders; a'ring rotatable in company with the pistons and mounted eccentrically in relation to the primary axis of rotation, with which ring the pistons cooperate without definite attachment, means for varying the eccentricity of the ring, a compensating ring engaging the piston heads and rotating with them and always maintaining position concentric with the eccentric ring,- and slippers capable of angular movement carried by the piston heads.

. 14. The fluid machine comprising the combination with a circular valve provided with ports, radialwcylinders rotatable relaacting as wear plates for the comprising the tive to said valve and'having ports cotip erating with the ports ofisaid valve and pistons operating in the cylinders; of a ring rotatable in company with mounted eccentrically in relation to the primary axis of rotation, with which ring the pistons coiiperate without definite attachment, means for varying the eccentricity of the ring, a ring engaging the piston heads and always malntaining position concentric with the eccentric ring, slippers capable of angular movement carried by the piston heads, and assages leading from the outside of said slippers and communicating with. fluid within the pistons and means for controlling the flow of fluid through said passages.

15. The fluid machine comprising the combination with a circular valve provided with ports, radial cylinders rotatable relarmg the pistons cooperate without definite.

and means carried by the piston the piston and mary axis of rotation, with which ring the pistons coiiperate without. definite attachment, means for varying the eccentricity" of t e ring, slippers capable of an lar 'movement carried by the piston hea s, and passages leading from the outside of said slippers and communicating with fluid within vices, the combination of a pump structure comprising the combination of a cylindrical valve provided with ports, radial cylinders rotatable relative to said valve and having ports cooperating radially with the ports of said valve, pistons operating in the cylinders, a ring mounted eccentrically in rela-- tion to the primary axis of rotation with which ring the pistons cooperate without definite attachment, and a compensating ring engaging the piston heads and rotatable in company with them and always maintaining position concentric with the eccentric ring and means for carying the eccentricity of said ring; ofa motor structure comprising the combination of a cylindrical valve provided with ports, radial cylinders rotatable relative to said valve and having ports cooperating radially with the ports of said valve and pistons operating in the cylinders; a ring mounted eccentrically in relation to theprimary axis of rotation with which ring the pistons cooperate without definite attachment, substantially as described.

17. In variable hydraulictransmission devices, the combination of' a pump structure comprising the combination with a circular valve provided with ports, radial cylinders rotatable relative to said valve and having ports cooperating with the ports of said valve, and pistons operating in' the cylinders; of a ring mounted eccentrically in relation to the primary axis of rotation with which ring the pistons coeperate without definite attachment, slippers capable of angular movement carried by the piston heads, and passages leading from the outside of said slippers and communicating with fluid within the pistons and means for controlling the flow of fluid through said passages; of a motor structure comprising the combination with a circular valve provided with ports, radial cylinders rotatable relative to said valve and having ports cooperating with the ports of said valve and pistons operating in the cylinders; of a ring mounted eccentrically-in relation to the primary axis of rotation with which ring the pistons cooperate without definite attachment, and means for varying the eccentricity of the ring, su stantially as described. W a

18-. In variable hydraulic transmission devices, the combination of a pump structure comprising the combination of a cylindrical valve provided with ports, radial vcylinders rotatable relative to said valve and having ports coiiperating radially with the ports of said valve, pistons operating in the cylinders; a ring mounted eccentrically in relation to the primary axis of rotation with which ring the pistons coiiperate without definite attachment, a ring engaging the piston heads and always maintaining position concentric with the eccentric ring, and slippers capable of angular movement carried by the piston heads and means for varying the eccentricity vices, the combination of a pump structure comprising the combination with a circular valve provided with ports, radial cylinders rotatable relative to said valve and having ports cooperating with the ports of said valve, and pistons operating in the cylinders; of a ring mounted eccentrically in relation to the primary axis of rotation, with which ring the pistons cooperate without definite attachment, a ring 1 engaging the piston heads and always maintaining position concentric with the eccentric ring, slippers capable of angular movement carried by'the piston heads, and passages leading from the outside of said slippers and communicating with fluid within the pistons and means for controlling the flow of liquid through said passages; of a motor structure comprising the combination with a circular valve provided with ports, radial cylinders rotatable relative to said valve and having ports cooperating with the ports of said valve and pistons operating in the cylinders; of a ring mounted eccentrically in relation to the primary axis of rotation with which ring the pistons cooperate without definite attachment, and means for varying the eccentricityof the ring, substantially as i described.

20. In variable hydraulic transmission devices, the combination of a pump structure comprising thecombination of a cylindrical valve provided with ports, radial cylinders rotatable relative to said valve and having ports cooperating radially with the ports of said 'valve, pistons operating in the cylin with theports 0 said valve, pistons operat- 1 of said ring; of a motor, structure comprising in the cylinders; a ring mounted eccen- In testimony whereof I have aflixed my trically in relation to the primary axis of -'signature in presence of two Witnesses. rotation with which ring the pistons 00- HENRY SELBY HELE-SHAW. operate without definite attachment, and Witnesses? 5 means for Varyingthe eccentricity of the AUG. A. THORNTON,

ring, substantially as'described. H. D. .JAMESON. 

